Threading machine



IWA

Feb. 9, 1932. s, T (5055 1,843,976

THREADING MACHINE Filed July l, 1929 6 Sheeis-Shee'b l 5507221947 7T Goss Feb. 9, 1932. s. T. Goss THREADING MACHINE Filed July l, 1929 6 Sheets-Sheet 2 v ScwZey Z Goss 351er A 6 Sheets-Sheet I5 Feb- 9, 1932 s. T. Goss THREADING MACHINE Filed July 1. 1929 fzg. 3

... l i i l @aus Feb. 9, 1932. s. T. Goss THREADING MACHINE Filedv July 1, 1929 e sheets-sheet 4 J8 75 ZJ mley 2.' Goss Feb. 9, v1932. s, T, @Q55 1,843,976

THREADING MACHINE Filed July l, 1929 6 Sheets-Sheet 5 136 fe 5 135 P (I y y f3! v V' w 31a/vanto@ Feb. 9, 1932. 5 T, Goss THREADING MACHINE Filed July l. 1929 6 Sheets-Sheet 6 Patented Feb. .9, 1932 UNITED STATES PATENT oFFlcE STANLEY T.,GOSS, 0F NEW BRITAIN, CONNEUEICUT, ABSIGNOB T0 THE GOSB AND DE LEEUW MACHINE COEPANYLOF NEW BRITAIN, CONNECI'IG'U T, A CORPORATION 0F CCNNECTICUT rnanamne MACHINE Application tiled July 1, 1929. Serial No. 375,154.

The present invention relates to metal working machines and particularly to machines of the type wherein threading operations are carried out by means of a threading tool, or threading tools, carried by a spindle, or spindles; the spindle or spindles, as 'the case may be, being rotated 1n one d1rect1on during the threading operation and being rotated in the opposite direction during the back off, that is, during the return movement of the Work or the tool, as the case may be.

As an instance of a use to which the improvements of the present invention may be applied, reference may be had to metal working machines of the chucking machines, but it is to be understood that, while the invention is particularly adaptable in that connection, the present disclosure is by way of illustration only, and.

that the invention is susceptible to various applications, modifications and changes, and that the terms here used are merely terms of description and not terms of limitation.

It has been, and still is, the general ractice to provide, in threading .machines o this sort, a clutchin the driving mechanism for the threading spindle for reversing the direction of rotation of the threading spindle. The use of clutches in this connection 1s open to numerous very serious objections and disadvantages, and while the manufacturers of machines of this sort have made numerous attempts to overcome these objections, so far as I am aware, they have not been successful. In cases where positively engaged clutches, such as dog clutches are employed, each time the clutch is engaged, the clutch itself, as Well as the entire mechanism, is subjected to severe shocks and racking strains which result in excessive wear on the parts, vibration and strains in the mechanism as a whole, and not infrequently, in faulty and inaccurate work. In positively -acting clutches, there is no slip or cushion action when the parts are engaged so that one part picks u y the other part very quickly and with a shoe which is imparted to the driving mechanism as a whole and to the threading spindle. Friction clutches have been employed in threadclass called automatic 4 ing machines, but these clutches are open t0 the objections that they burn, wear out nickly, require constant attention and a justment, and introduce objectionable slippage. Further objection to clutches in this connection is that the speed at which the threading spindle may be rotated must be limited to accommodate the duty which the clutch will perform and while on relatively small, light machines w ere the threading s indle is slowly rotated, clutches may prove airly satisfactory, on machines having relatively heavy arts and where the spindle rotates at a fairly good speed it is practically impossible to use such clutches, and this is particularly the case of a dog clutch.

The aim of the present invention is to provide an improved arrangement and construction wherein the use of clutches of any sort for starting, stopping and reversing t e direction of rotation of the tool spindle is eliminated together with the above noted and other disadvantages incident to the use of such clutches.

More particularly, an aim of the invention isv to provide an improved arrangement wherein the spindle may be started and stopped and the direction of rotation of the work spindle may be changed without introducing on the parts jars, shocks, excessive strains or Vibrations, so that wear and tear on the mechanism are largely eliminated, or at least reduced to a minimum; and wherein the practical rotative speeds of the threading spindle are not limited by the requirements or weaknesses of clutches, which means that the spindle may be run at a faster speed and the rate of production will be greater. Thus, my improved machine may be operated with extreme smoothness and qllietness at greater speeds, resulting in increased longevity of the machine and efficiency in its operation.

A further aim of the invention is torovide an improved arrangement which is c ar-" acterzed by its simplicity in construction, by its economy in manufacture, by its effectiveness in operation and by its strength and durability.

In accordance with the present invention, the machine is provided with a rotatable threading spindle, a motor for driving the spindle, and means for automatically start-- ing and stopping the spindle and reversing the direction of rotation of the motor at the proper times in order to effect a reversal of rotation of the spindle; the arrangement be -ing such that during the reversing operation, a perfect cushion action is obtained so that there is no unnecessary wear and strain upon the Working parts; while, at the same time, the parts are so co-related as to be properly synchronized in their co-action and relative movements.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement. of parts which will be exemplified in the construction hereinafter set forth and the scope of the applicatlon of which will be indicated in the appended claims.

In the accompanying drawings, I have shown my improvements incorporated in an automatic chucking machine of the type disclosed in the patent to A, L. De Leeuw, No. 1,626,187 granted April 26th, 1927, but it is to be understood that this disclosure is by way of exemplification only, and while my improvements are particularly adapted for useY in machinesof the De Leeuw type, they are not limited to that specific type of machine. In these drawings, only so much of the machine is illustrated as is necessary to disclose one application of the present invention.

In these drawings:

Figure 1 is a view in front elevation of a multiple spindle automatie-chucking-machine in which my improvements are incorporated;

Fig. 2 is an end View thereof, only a portion of the base being illustrated, and parts of the motor switch being omitted;

Fig. 3 is a side elevational view of the head stock, the motor for driving the threading spindle being shown in end elevation;

Fig. 4 is a sectional development ofthe gearing between the motor and the threadingr spindle;

Fig. 5 is a similar development in continuation of Fig. 4 and shows the arrangement for driving the trip which controls the motor switch;

Fig. 6 is a diagrammatical or conventional showing of a standard reversing controller;

Fig. 7 is an elevational view of the electric motor switch and the tripping mechanism therefor, the motor switch being illustrated in one extreme position;

Fig. 8 is a view similar to Fig. 7 but showing the tripping mechanism in loaded condition and the motor switch in neutral position; and

Fig. 9 is a View showing the spring con' trolled detent in longitudinal section, and the cooperating trip in elevation.

.Referring to the drawings in detail, the general arrangement and construction of the machine illustrated, insofar as it is similar to the disclosure of the said De Leeuw patent, will first be described and then the improvements of the present invention will be explained in'detail. As previously pointed out, the machine herein disclosed is illustrated by way of exempliication only, it being understood that my improvements are not limited to this specific type of machine, they having a broader application. For this and other reasons, all of the mechanisms with which the machine is normally equipped are not illustrated, and for an understanding of such mechanisms reference may be had to said De Leeuw patent.

The numeral 10 designates a. base having at one end guideways 11, on which is slidably mounted a work-supporting head comprising a slide 12, and an indexible turret 18, the latter having a plurality of work-holding or chucking devices 14 angularly arranged, only one of such devices heilig illustrated. Upon the other end of the base is ahead stock l5 in which is rotatably mounted a plurality of tool spindles 16. The work spindles are, of course, angularly spaced corresponding to the disposition of the chucking devices 14 so that, when the turret is in indexed position, the respective )ieces of work are aligned with the respectlve tools. Slidably mounted upon the head stock 15 is a slide or head 17 in which is mounted for rotary and axial movements a spindle 18 adapted to carry a tool, such as a threading tool, the same not being shown. This spindle may be supported in the same general manner as that shown in said De Leeuw patent and feeding devices similar to those disclosed in that patent may be employed for moving the spindle axially within its head. In Fig. 4, this arrangement is shown more or less diagrammatically. The spindle is journalled in bushings or bearing members 19 and 20 carried by the sliding head 17. For the purpose of feeding the spindle 18 longitudinally, the bearing member 19 is provided with a sleeve portion having an internal thread 21 with which cooperates an external thread 22 on a collar 22 fixed (by a key 23 and a nut 24) to the rear or left-hand end of the tool spindle. It will be understood that, when the spindle is turned in one direction, the threads 2l and 22 Will advance'it longitudinally in accordance with the pitch of the thread to be cut, and when the spindle is turned in the opposite direction, it will be returned or Withdrawn due to the threads 21 and 22. Obviously, the sliding head may carry more than one tool spindle. If it is desired to arrange the machine so that in ternal and external threading operations may be simultaneously carried out, there may/ be provided, at the forward end of the tool spindle, another set of cooperating feeding devices, such as disclosed in said De Leeuw patent. In the present instance, this other set of coo erating feedinv devices includes an externa ly threaded col ar 25 cooperating with an internal thread on the sleeve or bearing 20 (see Fig. 4). The collar 25 is fixed to an auxiliary spindle sleeve 27 splined, as at 28, upon the tool spindle 18 so that it will rotate therewith, but ma move lengthwise thereupon. It will be un erstood that,`when the tool spindle 18 is rotated, it will move longitudinally under the action of the cooperatin threads 21 and 22, as already describe and the spindle sleeve 27 will' move longitudinally under the action of the cooperating threaded members 20 and 25 at a rate that may be greater or less than the rate of feed of the tool spindle, according to the Vstructure of the threaded members respectively.

In order to positively co-relate the relative movements of the tool spindle head 17 and work supporting head, there is provided a liaison member in the form of a rod 30, shown in Fig. 1. This liaison member is similar in construction, function and purpose to the corresponding member shown in said De Leeuw patent. It is here shown as being fixed to the upper end of the slide 12 and slidably extending through an opening in an extension 31 arising from the tool splndle head 17. To each side of this extension, the rod 30 carries a nut 32 whereby the extent of relav tive `movement bet-Ween the slides 12 and 17 may be adjusted at will.

The various instrumentalities for moving the turret slide, for indexing the turret, and for locking the turret in indexed positions may be generally similar to those disclosed in said De Leeuw patent, and, therefore, the same are not disclosed in detail in the accompanying drawings. These various 1nstrumentalities and the several tool spindles 16.(but not the threading spindle) may be driven through the same general driving mechanism as that shown in said De Leeuw patent. This driving mechanism, insofar as it is disclosedin the accompanying drawings, ma include a main driving shaft 35 (see Figs. 2 and 3) extending transversely through the head stock and having on one end a gear 36 which may be driven from any suitable source of power, such as a motor. Insead of a gear, a belt pulley may be substituted. On the other end of the shaft 35 is a gear 37 meshing with a gear 38 on a shaft 39 which carries a bevel gear 40 meshing with a bevel gear 41 on a centrally located shaft 42. On the end of each tool spindle 16 is a gear 43, and between each of ,these gears and al gear 44 on the shaft 42 is an intermediate gear 45. This arrangement is identical to that shown in said De Leeuw patent and need not further be described. The feed shaft for the turret head and its co-ordinated mechanisms' is designated generally by the numeral 46 and may be driven from the main shaft. 35 in the same manner as is the corresponding shaft in said De Leeuw patent. To this end, there is interposed between the shafts 35 and 46 a set of gears and shafts including a pinion 46 on the shaft 35 mesh-- ing with a pinion 47 on a stub shaft 48; a bevel gear 49 on the stub shaft meshingwith a similar gear 50 on a countershaft 51; and a pinion 52 on the countershaft meshing with a pinion on the feed shaft 46.

The arrangement so far described is generally similar in construction and function to the arrangement disclosed in the said De Leeuw patent, it being understood, as heretofore pointed out, that this showing is by way of illustration only. vIn said De Leeuw patent, the various mechanisms above described, and the threading while that arrangement has the various advantages described in said De Leeuw patent, it necessitates a clutch in the train of gears leading to the threading spindle, and, as previously pointed out, such a clutch is o en to various disadvantages. It is the aim of the present invention to eliminate such a clutch together with its attendant objections. Also, it is an aim of the present invention to simplify the driving connections.

Referring now to the improvements of the present invention, there is provided, for the purpose of driving the threading spindle, an automatically controlled driving mechanism having a reversible electric motor. The driving connections between the motor and the threading spindle 18 are always maintained in engagement in the same relation, there being no break and make in these connections, as is necessary in case a. clutch is employed. The motor itself constitutes the source of power and also the means of reversing the direction of rotation of the threading spindle and the driving parts therefor. The motor, which may be either of the alternating or direct current type, is indicated by the letter M. It is preferably of the threephase type and is so constructed that, when the electrical connections leading to the motor are reversed, the direction of rotation of the motor is reversed. The motor may be mounted upon a bracket 60 fixed to a gear casing 61 which houses the driving connections a-nd which is located to one side of the tool spindle head.

The driving connection between the motor and the tool .spindle 18 will be readily understood from an examination of Figs. 2 and 4. The motor shaft 62 may be provided with a coupling 63 of any suitable type. Upon the spindle 18 are all/ driven from a. single source of power, and' motor shaft and within the casing 61 is a worm G4 meshing with a wo rm wheel 65 fixed to a shaft 66 which carries a pinion 67. The pinion 67, through intermediate fears 68 and 69, drives a gear 70 on a shaft 71 which carries, within the gear box, a gear 72 meshing with a gear 73. rlhis latter gear 73 meshes with a long pinion 74 which is journalled in, so as to slide with, the tool spindle head 17. Upon the tool spindle 18 is a gear 75 which is in mesh with the gear 74 and. which is adapted to move longitudinally of that gear while maintaining its meshing relation when the spindle head 17 is moved longitudinally. `The gears 67, (i8, 69 and 70 are change gears so that the speed of the threading spindle may be variously selected in accordancc with the requirements of the work to be performed.

The means for automatically controlling the direction of rotation of the motor, and, therefore, the direction of rotation of the tool spindle 18 will now be described with specitic reference. to the drawings, it heilig understood, however, that any suitable arrange.- mcnt of mechanism for this purpose may be employed. that shown in the drawings being by way of illustration only. The means for controllimgr the motor includes, generally, a motor switch (the operation of which is controlled, in part, by longitudinal movement ot the head 17) and a reversing mechanism of suitable sort controlled by the switch and in turn controllingr the motor.

The switch, which obviously may be of any suitable construction, is herein disclosed as including a circular body 8O ot' insulating material on the periphery ot which is a circuit closing member in the form ot' a section o'f a ring 81. The oscillatory switch unit including the disk and the closer 81) is fixed to a carrier 79 which is fixed to the outer end of a switch or rock shaft 89 journalled in the gear box 61. The switch is provided with three stationary terminals or contacts 83, 84 and 85, the latter being interposed angularly between the other two, and the arrangement being such that` in one position (see Fig. 7) ofthe switch unit, the circuit closing member is in contact with one outside terminal 8i and the central terminal 85; in another position, it is in contact with the central terminal and the other end terminal 83 (see Fig. 3), and in thc third or neutral posit-ion, it contaets only with the central terminal (see Fig. 8). These terminals may be of any suitable construction. those indicated by the numerals 83 and 84 being in the form of strips which are normally urged into operative position by springs 86. The central terminal 85 may be in the form of a block slidably mounted in a panel S7 of insulating material and suitably fixed to the outside of the gear box. The switch unit is moved into each oi its extreme positions with a quick snap movement, as

hereinafter described in detail, and, in order to prevent overthrow of the switch unit, there may be secured on the panell 87 a stop plate 88 having a projection 89 which lies between a pair ot pins 90 on the outer face ofthe carrier 79. ln Fig. 7, the switch unit. is shown in one of its eXtreme positions and in which position the upper pin 90 is in engagement with the projection 89.

The terminals 83, 84 and 85 are respectively connected by means of Wires 91, 92 and 93 to a motor reversing mechanism which may be of any suitable construction. Such mechanisms are old and well known. The same is not shown here in detail, although a standard type is illustrated diagrammatically in Fig. 6. As previously stated, the motor M is preferably of the three-phase type and is so constructed that, when the electrical connections leading to the motor are reversed, the direction of rotation of the motor shaft is reversed. Referring to Fig. 6, L-l, L-2 and L-3 indicate the three-phase line wires, and T-l, T-Q and T-B represent the three windings of the motor. Interposed between the WiresLe-l and T-l is a wire R-l in which is interposed a switch pole P-1. Between the line L3 and the wire T-1 is a Wire S-l in which is interposed a switch pole Q-l. Likewise, between the winding lL-3 and the respective line wires L-3 and L-1 are wires R-S and *U-3 in which are respectively interposed switch poles P-3 and Q-3. Between the neutral wire L-2 and the winding 'll-2 are two parallel wires lt-2 and S-2 in which are respectively interposed switch poles P-2 and Q--2. The switch poles Q-l, Q-Q and Q-3 are connected together and are adapted to be operated by a solenoid U connected in the wire 91 leading from the line wire L--l to the terminal 83 ofthe motor controlling switch. The poles P-1, P--2 and P-3 are connected together and are operated by a solenoid V interposed in the wire 92. T he neutral terminal of the switch is connected by a wire 93 to the line wire L-3. In explaining the operation of this reversing mechanism, it is sufficient to say that, when the circuit closing memberV 81 is in the position shown in Fig. 7 (where it contacts with the neutral terminal 85 and the lower terminal 84) the solenoid U is energized so as to close the switches Q--L Q and (,2-3, whereupon the winding 'l`-1 is connected to the line L-3 through the wire S-1, and the winding 'lL-3 is connected to the line L-l through the wire The central (so called for convenience only) winding T-Q is connected through the wire S-Q to the socalled neutral line L-2. lVhen the circuit closing member 81 is in neutral position, as

shown in Figs. 6 and 8, all of the polev switches are open and the motor is dead. When the circuit closing member is in its other extreme position, Where it engages the poles P-l, 137- 2 and P-3, is closed by the solenoid V, so that the line wlres L-1, L--2 and L-3 are' respectively -connected with the windin T--l1, T-2 and T--3 through the respctive wires R-1', R-2 and R-3.

e tripping mechanism for the motorv switch is controlled, in part, by a cont-rolling device which is shown in detail in Fig. 9, this controlling device being somewhat similar to the corresponding controlling device of said De Leeuw patent. U on the switch shaft 82 is a stop lever 100. ithin the wall of the gear box adjacent `the sliding head 17 is a controlling device includingma plug 101 in which is slidably mounted a ock-oif plunger 102 and a stop plunger 103. Interposed between the plungers is a pinion 104 co-acting with rack teeth on the plungers so that, when one plunger is moved in one direction, the other is moved in the opposite direction. The forward end of the plunger 102 is adapted to extend into the path of a trip pawl 105,

'. and the inner end of the plunger 103 is adapted to extend into the path of movement of the trip lever 100, as shown most clearly in Fig. 9. The trip pawl 105 is pivotally carried by a block 106 .which is adjustablysecured to the top surface of the sliding head 17. The operative end of the trip pawl is bevelled, as illustrated, and the pawl is normally held in the operative position shown in Fig. 9 by a spring pressed plunger 107.

The trip mechanism for moving the motor switch to its several positions will now be described. Upon a shaft 120, mounted in the gear box, is a tappet or dog wheel which includes a carrier 121 fixed to the end of the shaft 120, a trip disk 122 fixed to the carrier, and dogs or trips 123 and 124 adj ustably carried by the disk 122. These dogs may be of any suitable construction, but they are here shown as straddling the edge of the disk 122 and as being clamped thereon by means of screws 125. The shaft 120 is driven from the motor Min such manner vthat,`upon change of direction of rotation of the motor, the shaft 120 and the tappet wheel will change their directions of rotation. In the present instance, the shaft 120 is shown as extending transversely of'the shafts illustrated in Fig. 4. The shaft 120 has fixed to it a worm wheel 126 meshing with a worm 127 which rotates with the gear 73, as will be seen most clearly from Figs. 4 and 5. J ournalled for oscillating movement on a bearing 130 and located imlnediately behind the tappet wheel is a trip lever 131 having a wedge-shaped or bevelled nose 132 at the base of which are notches 133 and 134. Against this nose is adapted to engage a plunger 135.behind which is a spring 136. The lever 131 has an arm 137 which is connected by a pin 138 to a link 139. The pin has a head, as shown most clearly in Fig. 5, which extends out.- wardly into the path of movement of the dogs 123 and 124. The other end of the lever 139 is 'ivotally connected by a pivot 140 to a switc lever 141 'ournalled on a bearing 142 through which t e rock shaft 82 extends. rI his lever is adapted to operate between and to alternately engage a pair of angularly spaced apart studs 143 projecting vfrom the rear'face ofthe switch body 80.

' For the purpose of preventing the motor from overrunmng after the current is thrown ofi", there may be associated with the motor, or one of the parts driven thereby, a brake of any suitable sort. In the present instance,

I have shown for this purpose a magnetic brake associated with the coupling 63. 'The brake illustrated is of an old and well-known tlylpe and, as the particular construction t ereof forms no part of the present invention, it is shown more or less diagrammaticall in Fig. 3 and it is shown conventionally in igs. 2 and 6. The brake is designated, as a whole, b the letter'Y. It may have (referring to ig. 3) a pair of pivoted levers 150 having brake shoes 151 straddling the coupling 63. The shoes are normally urged .Y

into engagement with the coupling by a spring 152. For the purpose of movmg the brake parts to inoperative position, there is provided a solenoid or magnet 153 having an armature 154 adapted to o erate a lever 155. The solenoid 153 is suitalbly controlled, it being shown in Fig. 6 as being connected between the motor windings T-2 and T-3.

The operation of the machine will now be described. The non-longitudinally movable tool spindles 16 and the work supporting head are operated anddriven in the same general manner as in said De Leeuw patent rom a single source 'of power, as previously explained. The sliding head 17 for the threading spindle 18 is moved in timed relation to the sliding movements of the work supporting head through the liaison member or rod 30 in the same manner as is ex lained in said De Leeuw patent. Usually, t e nuts 32 carried by the llaison member are spaced apart further than the thickness of the extension 31 so that, at the beginning of each stroke of the work supportmg head, there is lost motion between the work supporting head and the sliding tool head 17.

In describing the cycle of operations of the machine, as a starting point it may be assumed that the work supporting head is moving towards the left from the position shown in Fig. 1; the motor switch is in the neutral position shown in Figs. 6 and 8; the tripping mechanism is in the position shown in Fig. 8; and the trip lever 100, carried by the switch shaft 82, is in the position shown in full lines in Fig. 9. In this position of the parts, the plunger 135 is loaded and is pressing the trip lever 131 clockwise, this lever being held against movement in that direction due to the engagement of the lever 100 against the plunger 103. The switch lever 141 is against the lower pin-143 of the motor switch. As the motor switch is in neutral position, the reversing mechanism is in the condition shown in Fig. 6; and the driving mechanism for the threading spindle 18, the threading spindle itself, the tappet wheel and the motor switch are stationary. The work supporting head continues its movement towards the left and the right hand nut 32 on the liaison member 30 picks u the sliding head 17 so that this sliding hea will now move in unison with the work supporting head towards the left. When the sliding head has thus been moved a predetermined extent, the trip pawl 105 engages the knockoli' plunger 102 thereby withdrawing the plunger 103 from the lever 100 with the result that the loaded plunger 135 will throw the trip lever 131 to the position shown in Fig.

7. When the trip lever is thus thrown, the switch is snapped into the position shown in Fig. 7, and the current is thrown onto the motor, and it may be assumed that the windings of the motor are now so connected as to cause the motor to rotate the threading spindlc in a direction to cut a thread. The lever will have moved to the dotted line position shown in F ig. 9 and, in which position, it holds the plunger 103 retracted. Since the threading spindle is now rotated, it wi'll also move axially due to the cooperating threads 21 and 22, and it may be assumed that the spindle lis advanced (or withdrawn, as the case may be, depending on the thread to be cut and the manner in which the machine is set up) to cut the thread. As soon as the motor is thus started, the tappet wheel will be driven in a counterclockwise direction (illustrated by the arrow in Fig. 7) so that the tappet 124 will move into engagement with the pin 138 and, thereafter, move that pin and the trip lever 131 to the dotted line position shown in Fig. 7 and, in which position, the nose 132 has -moved past center, whereupon the loaded plunger 135 will snap the trip lever 131 and the motor switch to the position shown in Fig. 3. It will be understood that, whenthe trip lever is snapped from the position shown in dotted lines Fig. 7 to the full line position shown in Fig. 3, the switch lever 141, which has been brought into engagement with the upper pin 143, will move the switch to the position shown in Fig. 3. While the tappet 124 is moved counterclockwise, from the position shown in Fig. 7 to a position Where it hasmoved the trip lever to the dotted line position shown in that figure, the threading operation may proceed. The dogs or tappets, of course, will have been adjusted in setting up the machine in accordance with the number of turns to be made by the threading tool during the cutting operation. When the motor switch is thrown to the positionY shown in Fig. 3, the trip lever 100 is moved to the dash position shown in Fig. 9 so as to permit the knock-olf plunger 102 to return to the o erative position shown in that figure. he windings on the motor M have now been re` versed through the standard reversing controller shown in Fig. 6, with the result that the driving mechanism for the spindle 18 and the spindle itself will be reversed and, owing to the cooperating-.threads 21 and 22, the threading spindle will be moved longitudinally on its non-cutting stroke, and while it is returning, the tappet wheel is rotated clockwise from the position shown in Fig. 3. At about the time the spindle has reached its full withdrawn position, the tappet 123 will engage the pin 138 and move the parts back to the original position; that is, the motor switch will be moved to the neutral position shown in Fig. 8 and the lever 100 will be held against the plunger 103, as shown by full lines in Fig. 9. The cycle may then be repeated. When the work supporting head moves to the right (referring to Fig. 1) the left hand nut 32 on the liaison rod 30 picks up the sliding head 17 and moves it to the left. When the head thus moves to the right, the trip pawl will not operate the knockoff plunger 102, since the pawl will swing on its pivot.

It will be observed from the foregoing description, taken in connection with the accompanying drawings, that, in the machine of the present invention, there are two separate drives, one for the tool spindles 16 and the work supporting head, and the other for the threading spindle 18, but, nevertheless, the operations and movements of the threading spindle are in timed relation to the operations and movements of the turret so that the various tooling operations may be so correlated as to be carried out simultaneously or in such desired sequences as to eliect a Saving of time in the performance of the machine. The operation of the motor drive for the threading spindle is initiated, or in part controlled, by the sliding movements of the head 17- which is connected by the liaison member 30 to the work supporting head so as to be moved thereby in timed relation thereto. While, in the foregoing description of the Ioperation' of the machlne, it has been assumed that, during the threading operation, the slide 17 is moving to the left and the threading spindle is being advanced, it is, of course, understood that that description is by way of illustration only, as the parts may be so tied up as to effect the threading operation on either the advance or return of the work supporting head or on the advance or return of the threading spindle.

It will further be observed that the drive for the threading spindle is devoid of any shown in the accompanying drawing make and break connections, such as dog or frictionv clutches, so that the disadvantages and objections to such'eonnections are entirely avoided. The motor M is, at all times, connected to the threading spindle. The starting, stopping and reversing of the rotative movements of the work spindle are all effected by controlling the motor so that such operations are carried out without any appreciable shocks, strains or jars, which means that wear and tear on the parts are largel eliminated, and the threading spindle itsel although it may be relatively heavy, may be rotated at a higher speed than has heretofore been possible, thus giving a higher' rate of production.

As many changes could be made in the above construction, and many apparently widely different embodiments of this invention could be made without departino' from the scope thereof, it is intended that aIl matter contained in the above description or shall be interpreted as illustrative and not in a limiting sense. l

It is also to be understood that the language used in the following claims is intended to cover all the generic and specific features of the invention herein described and allY statements of the scope ot the invention `which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

l. In a metal working machine, a threading sp-indle mounted for rotation in opposite directions, a reversible electric motor, a driving connection between said motor and spindle, a motor switch associated with said motor for controlling the direction of rotation thereof, a tappet wheel positively driven by said motor in timed relation to said spindle for controlling said switch, and means for snapping said switch into make positions.

2. In a metal working machine, a threading lspindle mounted for rotation in 'opposite directions, a reversible electric motor, a driving connection between said motor and spindle, a reversing controller through which the windings of said motor are made, broken and reversed; a motor switch associated with said controller and` having a neutral position, a position in which the windings of said motor are connected in such manner as to cause the motor to rotate in a given direction, and a third position in which themotor windings are. connected to cause the motor to rotate in the opposite direction; a tappet wheel positively driven by said motor in timed relation to said spindle for controlling said switch,

and means for snapping said switch into said .second and third positions.

3. In a metal working machine, a threading Spindle mounted for rotation in opposite directions. a reversible electric motor, a constant driveconneetion between said motor and spindle, a trip lever connected' to said `switch for moving the same to its several positions, a tappet wheel driven by said moto!l 1n timed relation to said spindle and having dogs adapted to move said tripjlev'er, and a spring'pressed plunger associated with said trip lever for throwing the same and said switch to their extreme positions. l

4. In a metal working'machine, ing spindle mounted for rotation in opposite directions and for reciprocatingmovement, a reversible electric motor, a connection between said motor and spindle, a reversing controller for said motor, a switch controlling said reversing controller, means driven by said motor in timed relation to said threading spindle for controlling said switch, and means controlled by the longitudinal movement of said spindle for holding the switch in neutral position at predetermined times.

5. In a metalworking machine, a threading spindle mounted for longitudinal movement and for rotary movement in opposite directions, driving means for said spindle including a reversible electric ,rnotor constantly connected to said spindle; a motor switch for controlling said motor having a neutral position in which said motor is dead, an extreme position in which said motor rotates in one direction, and a second extreme position in which said motor rotates in the opposite direction; means driven by vsaid motor in timed relation to said spindle forcentrolling said. switch, and a device controlled by the longitudinal movement of said spindle for holding said switch in neutral position for a predetermined period.

6. In a -metal working machine, a threading spindle mounted for rotary movement in opposite directions and for reciprocating movement, driving means for said spindle including a. reversible electric motor constantly connected to said spindle; a motor switch for controlling said motor and having a neutral position in which said motor is dead, an extreme position in which said motor rotates in one direction, and a second extreme position in which said motor rotates in the opposite direction; a said motor in timed relation to said spindle for controlling said switch, means for snapping said switch to each of its extreme positions, means for holding said switch in neuytral position after said tappet wheel has moved the switch in one direction to neutral position, and trip pawl for releasing said last mentioned means.

7. In a metal working machine, a sliding head, a threading spindle journalledrtherein for rotation in opposite directions and for feeding movement, a reversible electric motor, a connection between said motor and spindle, a reversing controller for said motor, a switch controlling said reversing controller tappet wheel driven by 1 means driven in timed relation to said threading spindle for controlling said switch, and means controlled by the longitudial move-- ment of said head for holding said switch in neutral position at predetermined periods.

8. In a metal working machine, a plurality of non-longitudinally movable tool spindles, a movable work carrier, a sliding head, a threading spindle journalled in said head for rotation in opposite directions, means for driving said plurality of spindles and said carrier, separate means for driving said threading spindle and including a reversible electric motor, and means' for automatically controlling said motor to thereby control the direction of rotation thereof and said threading spindle.

9. In a metal Working machine, a head stock, a forming tool journalled therein, a movable work carrier, means for driving said forming tool and work carrier, a sliding head, a threading spindle carried by said head, a connection between said sliding head and work carrier whereby the same move in timed relation, separate means for driving said threadingspindle and including a reversible electric motor, a motor switch controlling said motor, and meansmovable in unison with said head for initiating the cycle of movements of said motor.

10. In a metal working machine, a head stock, a plurality of non-longitudinally movable spindles journalled therein, a work carrier, means for driving said spindle and work carrier, a sliding head, a threading spindle journalled therein, mea ns for causing said threading spindle to move longitudinally in said head when the spindle is rotated. a connection between said work carrier and sliding head whereby the same move in timed relation, separate means for driving said threading spindle and including a reversible electric motor, a motor switch for controlling said motor, means driven by said motor iu timed relation to said threading spindle for controlling said switch, means for holding said switch in neutral position at predetermined times, and means carried by said bead for releasing said last mentioned means and thus initiating the cycle of movements of said motor switch.

11. In a machine ofthe character described, a threading spindle mounted for rotation in opposite directions, screw means operatively and positively associated with said spindle for moving the same longitudinally when rotated in timed relation to its rotary movement, a reversible electric motor, a constant unbroken connection between said motor and said spindle, a motor switch for controlling the starting, stopping and reversing of said motor, and means driven by said motor in timed relation to said spindle for controlling said switch.

12. In a machine of the character described,

a threading spindle mounted for rotation in opposite directions, means operatively associated with the spindle for causing longitudinal movement of the spindle incident to rotation of the spindle, a reversible electric motor, a constant connection between said motor and spindle, a reversing controller through which the windings of sald motor are made, broken and reversed so as to start, stop and reverse the direction of rotation of the motor, a motor switch for controlling said controller, means driven by said motor and in timed relation to said spindle for controlling said motor switch, and trip means effected by the longitudinal movement of said spindle for initiating the cycle of operations.

13. In a machine of the character described, av sliding head, a threading spindle journaled therein, means for causing said threadin spindle to move longitudinally in said head 5 when the spindle is rotated, a Work carrier having a turret, a connection between said work carrier and sliding head whereby the same move in unison, means for moving said head and work carrier, independent means for driving said threading spindle and including a reversible motor, a motor switch for conp trolling said motor, means driven yby said f" motor in timed relation to said threading spindle for controlling said switch, and trip means controlled by the longitudinal movement of said head for initiating the cycle of movements of said motor switch.

14. In a metal working machine, a threading spindle mounted for rotation in opposite directions, means for positively rotating and longitudinally moving said spindle in timed relation so that each point of the spindle moves in-the path of a predetermined helix, said means including a reversible electric motor, and means for automatically controlling said motor to thereby control the direction of rotation of the motor and the spindle driven thereby.

15. In a metal working machine, a threading spindle mounted for rotation in opposite directions, means for positively moving said spindle longitudinally when rotated and in timed relation to its rotary movement wherebyreach point of the spindle moves in the path of a predetermined helix, driving means for said spindle and including a reversible motor, and means for automatically controllin said motor to thereby control the direction o rotation and the direction of longitudinal movement of the spindle.

STANLEY T. GOSS. 

